<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
     <style>
        /* 后面覆盖前面的；不同属性叠加 */
        div {
            color: red;
            font-size: 30px;
        }

        div {
            color: blue;
            font-weight: 700;
        }
     </style>
</head>
<body>
    <div>div 标签</div>
</body>
</html>